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LIFE, IN ITS HIGHER FORMS 



the ground and becomes a fixed point from wjience to set 

 out anew, This motion is beautifully seen when a Snake 

 is climbing over an angle to get upon a flat surface. When 

 the animal is moving, it alters its shape from a circular or 

 oval form to something approaching a triangle, of which 

 the surface on the ground forms the base. The Coluber 

 and Boa having large abdominal scuta, which may be con- 

 sidered as hoofs or shoes, are the best fitted for this kind 



of progressive motion An observation of Sir 



Joseph Banks, during the exhibition of a Coluber of unusual 

 size, first led to this discovery. While it was moving 

 briskly along the carpet, he said he thought he saw the 

 ribs come forward in succession, like the feet of a cater- 

 pillar. This remark led me to examine the animal's motion 

 with more accuracy, and, on putting the hand under its 

 belly, while the Snake was in the act of passing over the 

 palm, the ends of the ribs were distinctly felt pressing upon 

 the surface in regular succession, so us to leave no doubt 

 of the ribs forming so many pairs of levers, by which the 

 animal moves its body from place to place." 



Many of the Serpents habitually live among the branches 

 of trees, and most species can climb the smooth trunks with 

 facility : not, however, by encircling the branch or bole in 

 soiral coils, as artists who probably never saw a Snake in 

 motion ridiculously represent them, but by a direct upward 

 gliding, the body extended nearly in a straight line. 



As all the Serpent tribes are carnivorous, and almost all 

 feed on living active animals, often of much greater bulk 

 than the diameter of their own mouths, while yet they 

 invariably swallow their prey entire, it becomes a problem 

 of interest how this is effected. They are fitted for their 



